Stupid Question

Questions or comments about hiking in general? Post them here!
Post Reply
User avatar
dlarson
Site Admin
Posts: 429
Joined: Tue Jul 08, 2008 10:02 pm
Location: minnesota

Stupid Question

Post by dlarson » Mon Aug 04, 2008 11:06 pm

Alright, this is going to sound real stupid but here it goes.
When you guys are testing your stoves and you say "1oz of fuel" are you talking volume or mass, i.e. - fl oz or oz.?
I presume your talking fluid ounces but I just want to be clear on this.

Also, what is the appropriate water temperature for testing how long it takes to boil?
And do you wait for stoves to prime (when required) before placing the water over the stove but not with others? I suppose with stoves like the Whitebox waiting is required but with a Pepsi Jet and a pot stand I'll usually toss the water on right away and take advantage of the priming heat.

***edit***
One last thing, is priming fuel included in the measure of fuel used?




Scot Adams wrote:If there are no stupid questions, then what kind of questions do stupid people ask? Do they get smart just in time to ask questions?
-Scott Adams
"Hiking is just walking where it's O.K. to pee." -Demetri Martin

User avatar
DarenN
Posts: 2816
Joined: Wed Feb 06, 2008 11:46 am
Location: Surrey, B.C. Canada

Re: Stupid Question

Post by DarenN » Mon Aug 04, 2008 11:55 pm

fuel is measured by volume. 1/2oz equals 15ml.

i can't get Denatured Alcohol here in Canada and have to use Methyl Hydrate.
15ml of D/A carries the equivalent btu's of 18ml of M/H. Zelph and i have exchanged some stoves and proven this.

we try to start with 2cups of water at seventy degrees F. call it room temp. room temp for stove, fuel, pot and stand. no windscreen, but no disturbing air currents either. as Zelph once said, "just sit down and watch the water boil." timer starts when the pot hits the stand.

i'll let someone else answer to the priming fuel question. if a stove i build requires priming i call it a failure. just my preference.

Daren........
"I'd rather be happy than right." Slartibartfast

oops56
Posts: 1920
Joined: Wed Sep 19, 2007 11:31 am

Re: Stupid Question

Post by oops56 » Tue Aug 05, 2008 1:54 am

If i have to use a prime i let it die down then put pot on but you loose some burn time if prime to much it is to long get very hi flame and stove will boil the alcohol to hot total burn be short.Now on my wick that has no prime i wait till its up and burning good then pot then time. Gee i hope i said this right :? yet
Man play with fire man get burnt

User avatar
zelph
Posts: 15834
Joined: Tue Aug 14, 2007 1:53 pm

Re: Stupid Question

Post by zelph » Tue Aug 05, 2008 9:41 am

I agree with DarenN. Especially about a stove that needs to be primed is a failure. The WBS needs 1.75 min of burnning time before you can put the pot on. That's alot of priming time, lots of fuel wasted.

Oops is heading in the right direction by using wick for his stoves, no priming necessary :D The Tikki wick method he has demonstrated is by far the best way to go to make an efficient, good performing burner. The fibers of the wick are oriented verticle to get the fuel up to the surface where it makes for easy cold weather starting. The material used in the SS StarLyte Ultralyte works on the same principal, verticaly oriented fibers in very close proximity to each other.
http://www.woodgaz-stove.com/

User avatar
Skidsteer
Posts: 555
Joined: Fri Aug 17, 2007 2:10 pm
Location: Leisure Acres

Re: Stupid Question

Post by Skidsteer » Tue Aug 05, 2008 7:32 pm

15 ml is a half ounce; 30 ml is one ounce. That's how I figure it for my tests.

If I build a stove that requires priming(rare), then the priming fuel is part of the total fuel claimed for the 2-cup boil.
Skids

Insanity: doing the same thing over and over again and expecting different results.
Albert Einstein, (attributed)
Image

User avatar
dlarson
Site Admin
Posts: 429
Joined: Tue Jul 08, 2008 10:02 pm
Location: minnesota

Re: Stupid Question

Post by dlarson » Wed Aug 06, 2008 12:30 am

Thanks folks. Good to know.
I guess I don't feel as strongly about the priming thing though. I consider it one of the inherent side effects of using alcohol.
Do any of you have any particular tools that you have found to work well for measuring your fuel? Syringes, graduated cylinders, shot glasses?
"Hiking is just walking where it's O.K. to pee." -Demetri Martin

Tony
Posts: 293
Joined: Thu Sep 27, 2007 11:46 pm
Location: Canberra Australia
Contact:

Re: Stupid Question

Post by Tony » Wed Aug 06, 2008 2:21 am

Hi dlarson,
Alright, this is going to sound real stupid but here it goes.
When you guys are testing your stoves and you say "1oz of fuel" are you talking volume or mass, i.e. - fl oz or oz.?
I presume your talking fluid ounces but I just want to be clear on this.
An ounce (oz) is a measure of weight or mass.

A fluid ounce (fl oz) is a measure of volume but there are two fl oz an imperial or UK fl oz and the US fl oz, they are different and it should be stated which one you are using eg; US fl oz.

If I see published results " I used x oz of fuel to boil x oz of water" I turn off and dismiss them as I am unable to trust them.

The best way is go metric.

check this site out http://www.nist.gov/ it is all there.
Also, what is the appropriate water temperature for testing how long it takes to boil?
I have my views on this, it is not important at what temperature you start at but what you finish at (water boils at different temperatures depending on several factors), record temperature rise and then you can alway extrapolate results.
And do you wait for stoves to prime (when required) before placing the water over the stove but not with others? I suppose with stoves like the Whitebox waiting is required but with a Pepsi Jet and a pot stand I'll usually toss the water on right away and take advantage of the priming heat.

***edit***
One last thing, is priming fuel included in the measure of fuel used?
Always use the fuel used in priming in results and if possible use priming fuel to heat, or better still get a canister stove.

Tony

User avatar
Skidsteer
Posts: 555
Joined: Fri Aug 17, 2007 2:10 pm
Location: Leisure Acres

Re: Stupid Question

Post by Skidsteer » Wed Aug 06, 2008 7:59 am

dlarson wrote:Thanks folks. Good to know.
Do any of you have any particular tools that you have found to work well for measuring your fuel? Syringes, graduated cylinders, shot glasses?
I use my stove. One filling equals 15 ml. If needed I can add up to 30 ml total in 7.5 ml increments.


Image

If using a different stove, I use the cap from my fuel bottle or just eyeball it. Of course, that's just when I'm hiking. For testing, I use a syringe.
Skids

Insanity: doing the same thing over and over again and expecting different results.
Albert Einstein, (attributed)
Image

Post Reply